Revisiting the interacting model of new agegraphic dark energy

In this paper, a new version of the interacting model of new agegraphic dark energy (INADE) is proposed and analyzed in detail. The interaction between dark energy and dark matter is reconsidered. The interaction term Q = bH₀ρ_de^αρ_dm^1‑α is adopted, which abandons the Hubble expansion rate H and involves both ρ_de and ρ_dm. Moreover, the new initial condition for the agegraphic dark energy is used, which solves the problem of accommodating baryon matter and radiation in the model. The solution of the model can be given using an iterative algorithm. A concrete example for the calculation of the model is given. Furthermore, the model is constrained by using the combined Planck data (Planck+BAO+SNIa+H₀) and the combined WMAP-9 data (WMAP+BAO+SNIa+H₀). Three typical cases are considered: (A) Q = bH₀ρ_de, (B) Q = bH₀ √ρ_deρ_dm, and (C) Q = bH₀ρ_dm, which correspond to α = 1, 1/2, and 0, respectively. The departures of the models from the ΛCDM model are measured by the ΔBIC and ΔAIC values. It is shown that the INADE model is better than the NADE model in the fit, and the INADE(A) model is the best in fitting data among the three cases.